Environmental influence on developmental plasticity impacts a wide diversity of animal life from insects to humans. We now understand the epigenetic basis for many of these altered phenotypes. The five environmental factors of nutrition, behavior, stress, toxins and stochasticity work individually and in concert to affect the developing epigenome. During early embryogenesis, epigenetic marks, such as DNA methylation, are reset at specific times. Two waves of global demethylation and reestablishment of methylation frame the sensitive times for early environmental influences and will be the focus of this review. Gene transcription, translation and post-translational modification of chromatin remodeling complexes are three mechanisms affected by developmental exposure to environmental factors. To illustrate how changes in the early environment profoundly affect these mechanisms, we provide examples throughout the animal kingdom. Herein we review the history, time points and mechanisms of epigenetic geneenvironment interaction.
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sequence specific manner.77 The cell-to-cell inheritance of this We thank Dr. Craig Harris for critically reading this manuscript mark is thereby disrupted and has implications for development. and Dr. Carl Anderson for assistance with figures. Research Any environmental influences that alter the activity of EZH2, or support was provided by NIH grants T32 ES007062 (C.F.), its upstream CDK enzymes, can thereby have widespread devel-ES017524 (D.C.D.), and the University of Michigan NIEHS opmental effects lasting into adulthood. Placental mammals also P30 Core Center P30ES017885 as well as NIH/EPA P20 grant have Rex1, a DNA-binding transcription factor thought to target ES018171/RD 83480001.
- DNA methylation
- Environmental epigenomics